SBIR Phase II: Using a novel RNA therapy to immunize trees and vines against deadly bacteria

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project is to develop the first small RNA-based immunization approach for several deadly plant diseases including Xylella fastidiosa (Xf) in grapevines. Xf diseases include (1) Olive Quick Decline Syndrome, which is currently threatening the entire Southern European olive industry and killing trees that are over 1,000 years old; (2) Pierce’s Disease, which has severely damaged Southern California vineyards; and (3) Citrus Variegated Chlorosis, which is one of several diseases threatening the citrus industry. In addition, the project seeks to develop a proof-of-concept inoculations against several other of the most impactful viral and fungal diseases affect grapevines in the United States. A single inoculation can potentially provide lifetime protection against multiple pathogens while not harming the tree. In the absence of treatment, in a few decades, citrus, olive, and many other valuable crops that produce food for millions of people may cease to exist outside of insect-protective structures like greenhouses. The technology being scaled-up is based on a novel infectious RNA that can be used as a delivery vehicle for anti-pathogenic agents. The proposed project has 4 key goals: (1) optimizing siRNAs against Xf and further improving the inoculation process for grapevine crops; (2) targeting Xf in grapevine crops; (3) targeting grapevine red blotch virus; (4) targeting downy mildew of grape caused by Plasmopara viticola fungus. Efficacy will be demonstrated in separate trials for each pathogen, ultimately laying the foundation for a single integrated product that would be able to protect grapevines against multiple deadly pathogens. This technology seeks to build on validations in the model plant N. bethamiana by scaling up to a full demonstration of efficacy in grapevines. Once efficacy is demonstrated, then field trials will be conducted. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.